130 STATES OF INSECTS. (Larva.) 
joints*, which seems the most natural number ; and the 
former are limited to three. Both vary between these 
numbers, and one joint. ‘The joints, though commonly 
simple, are sometimes branched. ‘This is the case with 
one I met with in considerable numbers upon the Tur- 
nip, in October 1808, the second joint of the palpi of 
which sends forth near the apex an internal branch. In 
the larva of the Cossus, as Lyonnet informs us?, the joints 
of the palpi are retractile, so that the whole of the organ 
may be nearly withdrawn. 
After thus describing the head of larvee, and its prin- 
cipal organs, we must next say something upon the re- 
mainder of the body, or what constitutes the 
2. Trunk and Abdomen: which I shall consider under 
one article. These are composed of several segments or 
rings, to which the feet and other appendages of the 
body are fixed. The form of these segments, or that of 
their vertical section, varies considerably : ‘in many Lepi- 
doptera, the wire-worm, &c., it would be nearly circular ; 
in others a greater or less segment of a circle would re- 
present it; and in some, perhaps, it would consist of two 
such segments applied together. Their lower surface is 
generally nearly plane. Their most natural number, 
without the head and including the anal segment, is 
twelve: this they seldom exceed, and perhaps never 
fourteen. ‘The three first segments are those which re- 
present the ¢runk of the perfect insect, and to which the 
six anterior legs when present are affixed. In general, 
* At first in the Dytisci they appear to have five joints; but, as I 
before observed, the first joint must be regarded as representing the 
maxilla. > Lyonnet Anatom. 55, 58. 
